Two-piece insert



Dec. 29, 1964 RosAN ETAL 3,163,197

TWO-PIECE INSERT Filed Jan. 9, 1961 2 Sheets-Sheet l IIII 7717/5 IIIII" ,JNVENTQRS Dec. 29, 1964 J. RosAN ETAL 3,163,197

TWO-PIECE INSERT Filed Jan. 9, 1961 2 Sheets-Sheet 2 ggg. 5

Anali/var i United States Patent 3,163,197 TWG-PECE INSERT Ios Rosan, San .lean Capistrano, and Albert .lach La Torre, Santa Ana, Caiif., assignors to Rosan Engineeringl Corporation, a corporation of Caiiforna Filed Een. 9, 1961, Ser. No. 81,363 5 Ciairns. (Cl. 151-4L73) This invention relates to a novel insert construction, and more specifically to a two-piece insert comprising a pair of interengaging tubular internally and externally threaded members, one of which is adapted to be received and locked within a threaded bore or socket in a parent body, and the other is adapted to be received and locked within the rst member. The inner-threaded member is adapted to receive and lock in position a third externally threaded member.

The invention finds special, though not exclusive application, in cases wherein it is desired to fasten parts to a body of relatively soft or malleable material, such as aluminum, magnesium, alloys of aluminum and magnesium, and the like, as, for example, in aircraft construction, especi-ally in cases where it is desired or required to remove or replace the part to be fastened. It has been found that repeated removal and insertion of threaded fasteners in a threaded bore of malleable material soon causes galling of the threaded bore, making it impossible to obtain a tight connection.

Ithas been suggested to use a threaded insert of harder material, such :as steel, and to connect the fastener element to the insert. This arrangement has been satisfactory. Inthe use of such threaded inserts, it has been found advisable to lock the insert in the threaded borel of the parent body, as there is a tendency for the insert to work loose in the absence of some locking means.

`One of the arrangements heretofore used involves the use of locking rings or similar structure, which have proved to be eifective. The present invention affords a cost reduction over such means, however.

It is an object of the invention, therefore, to provide a novel insert that is simple in` construction and which can be readily locked in a threaded bore in a parent body with or Without the use of additional parts, such as locking rings and the like.

It is a further object to provide a novel two-piece threaded insert consisting of a pair of intertting threaded sleeves, the outer of which can be locally deformed into locking engagement with a body of parent material, and the inner of which can be locally deformed into locking engagement with the outer sleeve.

lt is a still further object to provide a novel twopiece threaded insert consisting of `a pair of interitting threaded sleeves of relatively hard material, the inner of which is adapted to receive a threaded fastening element, and which canlreadily be replaced when worn or when desired.

It is a still further object to provide a novel twopievce insert consisting of a pair of intertting threaded sleeves, in which one end of the outer sleeve has a locking formation adapted to be spread outwardly into locking engagement with the surrounding material of a parent body, and in which the inner sleeve is interlockedwith the other end of the outer sleeve.

l26 alternating with serrations 2?.

The attainment Vof the above objects, as well as other objects, will be evident from the following description when considered with the attached drawings in which:

FIGURE l is a top plan'view of a irst embodiment of a two-piece insert;

FIGURE 2 is an elevation view in quarter section of the first embodiment in locked position within a threaded bore or socket of a parent body shown in broken lines;

FIGURE 3 is an elevation view in quarter section of the outer tubular member of the two-piece insert of FIGURES l and 2;

FIGURE 4 is an elevation view in quarter section of the inner tubular member of the two-piece insert of FGURES l and2; A Y

FiGURE 5 is a sectional view with a quarter elevation of the inner tubular member of`a second embodiment of a two-piece insert;

FI'GURE 6 is a partial sectional view of a third ern bodiment of a two-piece insert;

FIGURE 7 is `an exploded view of a fourth embodiment of a two-piece insert; and

FIGURE 8 is an elevation view, in quarter section, of a variation of the embodiment of FIGURE 7.

In the form of the invention shown in FIGURES 1 to 4, the insert in its entirety is designated by the numeral itl, and comprises an outer tubular member orv sleeve 12, and an inner tubular member or sleeve 14, the inner sleeve :adapted to intert the outer sleeve, `as described hereinafter.

The outer tubular member l2 comprises a cylindrical body 16 having external threads 13 extending throughout its entire length, and an internally 'threaded bore forming threads 24 defined between counterbores 20 and 22. The counterbores 20 and 22 may have the same or diiferent diameters, but the diameter should be at least equal to the root diameter of the internal threads 24, to allow the internal threaded member to enter the outer tubular member, as appearing hereinafter. One or two convolutions on one end of the external threads 18 are knurled to form a series of spaced yaxial grooves As shown, these serrations are formed ontthe upper end, but, since the tubul-ar member 12 is symmetrical, it is evident that these serrations can be formed on either end, or if desired, on both ends. A Y

The inner tubular member i4 comprises a substantially cylindrical body 30 having external threads 32 extending throughout the length thereof, an internally threaded bore having internal threads 36, having within one end 31 a counterbore 3.4 as seen in FIGURE 4. The counterbore 34 has a cylindrical wall with a diameter fat least as great as the root diameter of the internal threads 36. Intermediate the ends of the externalV threads 32, the roots are inwardly deformed, as shown at 38, to produce an internal enlargement 4t) causing an interference lit with the external threads of a fastener, not show-n, that may be threaded in mating relation with the internal threads 36. A series of axial grooves 42 are formed, as by knurling, in one or two convolutions adjoining the end of the external threads 32 in the zonesurrounding the counterborelt, to form a series of ser+- rations 44 for a purpose to be set forth hereinafter.

The insert 10 is adapted to be threaded into an iuternally threadedA bore or socket 46 of a parentfbody I 48, having a smooth wall counterbore 5t?, shown in. i

dotted lines in FIGURE 2. The diameter and pitch of Vthe internally threaded. bore 46 correspond to those of the external threadsl on the outer tubular member 12, and the diameter ofthe counterbore is slightly larger than the crest diameter'of the external threads I8, so that thereV will be no interferencewith the threading of the tubular member 12 into the parent body 4S from the,`

Vupper end shown in FIGURE 2. The outer tubular `member 12 may beV screwed into the threaded .bore 46 to the position shown inFIGURE 2 in which the upper end 17 of the tubular member lies slightly'below the upper surface 47 of the parentbody 48.

The parent body may be some metallic structure such as an airplane wing., fuselage, Cowling or other part, made'of relatively soft'or Vmalleable material such as aluminum, magnesium, and alloys of aluminum `or magnesium or other metal, while the insert I@ may be'made ofa much harder material, such as,.for example, steel, cast iron, or the like. Various materials may be employed, but it is importantthat the material of the insert must be considerably harder or less malleable than the.V .material of the parent body in `which it is inserted. For example, both the parent'body and the insert may be -made of steel', or they both may be made of plastics, but ineitherevent, the insert must be made of harder material.

With outer A'tubular member 12 of insert It) in the position shown in FIGURE 2, a suitable expander tool lmay be inserted into'the upper end thereof, in the zone' defined by the'counterbore V2.0,fand radial pressure applied to the wall of thefcounterbore to produce al flare, as shown irl-the upper left hand corner of'FIGURE 2, which will force the serrations 2S 'into the malleable material forming the wall of the counterbore 26, displac- Ving someV of'this material into the channel 29 between consecutive convolutions or into the grooves 26, thereby forming a locking interconnection between the locking f formations or serrations 28 and the body of parent material 4S. The inner tubular member 14 may thenrbe 40. Vthe lower ends ofthe outer tubular member 12Band amano? It will be noted that the externalthreads .18A on the outer tubular member 12A do noty extend the full length of the cylindrical body 16A, but terminatea short distance from the lower end VSIA thereof, to provide a cylindrical portion 52, having a'counterbore 22A.` In this form of the invention, the inner and outer members are interloclred in the same manner described in .connection with the modification of FIGURES '1 to 4.

This form of the'invention can be used in a socket or aperture in a parent body in the same manner as shown in FIGURE 2, but finds specialapplication inusituations where the insert is longer than the aperture in the parent body, whereby the cylindrical portion 52 mayV extend beyond the surface of the tubular body. In such arrangement, a ring or backing tool can be applied around the cylindrical'portion 52 to prevent flaring or deformation Y thereof when the lower end of the inner tubular body externalthr'eads 18B extend-nearly Ythe full length of. the cylindrical body 16B, terminating ka short distancek fromthe vlow'errend thereof. to lprovidea cylindrical por- Ation 54 having airsmooth outer wall, and a smooth inner wallformed byacounterboree22B.' The external threads V'32B on the inner'tubular member 14B terminate a short distance fromthe lower end thereof, forming Ia cylindrical portion Se' having a diameter substantially the same, or slightly smaller, than the diameter of the counterbore 22B. This cylindrical portion 56 is provided with a counterbore`53. A locking'. interconnection between the inner tubularV member `14B can be formed by a welded threaded into the outer tubular member I2 into a posi` tion corresponding to that shown in FIGURE 2, in which the lower end ofthe threads E52 lie Vin the zone de'iinedA by thel counterbore22. The inner tubular` member 14 may be inserted from either end of the outer tubularY v member, depending upon whether the internally threaded bore 46 isformed in an aperture or in aV socket. When so positioned, an expander tool can'bepositioned in the zone formed by thecounterbore 34, and` aA radial pressure applied to theA wall circumferentially .inthe area indicated at 35 toA force the serrations44 into the material of the cylindrical body 16, as shown in the lower left hand corner of FIGURE 2, providing a locking interconnection between the locking'formations on the cylindrical bodyjand the Wall of :the counterbore 22..`

It will be'. lunderstood that 4Vthe inner tubularv member 14 may be threaded :into the outer tubular .member 12 beforethe insert, as a-whole, is. threaded in the threaded bore d, andthe walls thenexpanded to obtain. the

Y' beyond'the'threaded bore, a .weld can be .formedbyp above locking connections,Y or, 'if preferred, the outer tubular member may first be` inserted, and the inner tu-Y bular member I4 can then be inserted, andthe wallsV `ilared outward simultaneously or in turn, as desired, or

spot, butt or fusion welded.

FIGURE `5' illustrates a modification of the insert of FIGURES 1 to 4 in which. one end of the outer tubular member, opposite the endY carrying the lockingformaf `tions or serrations (not shown), is cylindrical and vfree from internal andexternal threads. Only the lower end A `VVof the insert is shown in FIGURE '5, and the parts "thereof, correspondingto the parts of .the modication. shown in yFIGURES 1 Vto 4,V are designated by the same .reference numeral with the addition of the letterA.

joint between the wall of the counterbore 22B andthe Y outer wall of the cylindrical portion 56. l The 'numeral p62 indicates,diagrammatically a joint formed by engaging a pair of welding electrodes;with1opposed points on Vthe wall of the counterbore 58, and the external wall of the cylindrical portion 54, during manufacture.` Cur-l rent may be passedV therethrufrom a suitable source, not shown, to form aspot weld between the cylindrical portions 54 and S6, and the electrodes thereafter removed. It is evident, in order to obtain such. a welded joint, that the cylindricalportions 54 and 56 should extend outside the threaded Vbore 46 in the lparent body Y48, as shown in FIGURE 2. It is also evident that', be-

cause of the diameter ofthe cylindrical. portion.56, the inner tubular member 14B must be threaded from the bottom or lower end of the outer cylindrical member IZB of FIGURE 6.' A Y VVIf the cylindrical .portions54and 56,4110 not extend other methods.

FIGURE 7 illustrates another modification of the formV Y of insert shown inV FIGURES -1 through 4, *having a diierent formof vinterlocking arrangement between the outer vtubular member 12C and they inner tubular member I4C. Theupper or outer end of the insert is not Y illustrated in FIGURE 7, but'isidentical with thatshown in FIGURES 1 through 4, and corresponding partsin FIGURE`7 are designated by the samenumerals' with the addition of the letter C. In' this .formof the invention, the external threads 13C'on the cylindrical body 16C terminate somewhat short. of the lower or ,innerl end,.to form a cylindrical portion 64 having a pair of axially extending, diametrically opposed, tongues 66.' The external threads 32C on the cylindrical body 30C of the inner tubular member 14C terminate short of the lower end thereof, providing a cylindrical portion 68. A pair of diametrieally opposed slots 70 are formed in the cylindrical portion 6 8, having a width and a length suiicient to receive the tongues V66 when the latter are deformed or bent inwardly to extend within the slots. In this form of the invention, the outer tubular member I2C and the inner tubular member 14C may Abe positioned within the threaded bore of a parent body, not shown, and the tongues 66 aligned withV the slots 76, whereupon, by suitable tools, the tongues may be inwardly deformed to enter the slots 70. ASuch Va deformation provides an easily formed and rigid interlock between the inner and outer tubular members. tage of this arrangement lies in the fact that the tongues can easily be deformed to their original position to facilitate removal and replacement of the inner tubular member MC when desired.

It is evident that, alternatively, the tongues 66 can be provided in the inner tubular member 14C and the slots 70 in the outer tubular member 12C. It is also evident that the number of tongues need not be the same as the number of slots, or that the tongues and slots be oppositely disposed or equally spaced around the periphery. For instance, one or two tongues and a greater number, or even a single, slot may be provided. Y

FIGURE 8 illustrates a modified arrangement of the tongue and slot connection of FIGURE 7. The upper end of the insert 10D of FIGURE 8, not illustrated, is identical with that of FIGURES l through 4, and corresponding parts in FIGURE 8 are designated by the same reference numeral with the addition of the letter D.

In FIGURE 8, the external threads 18D terminate a short distance from the lower end to form a cylindrical portion 80. Likewise, the external threads 32D on the inner tubular member 14D terminate a short distance from the lower end to form a smooth cylindrical portion 74. The threaded bore 36D in the inner tubular member 14D is counterbored at 7S, the diameter thereof being at least as large as the root diameter of the internal threads 36D. The external diameter of the cylindrical portion 74 is shown as being somewhat greater than the diameter of the crest of the inner threads 24D and somewhat less than the diameter of the counterbore 22D in the outer tubular member 12D, to provide a thickened wall lin which a plurality of axially extending slots 76 are formed. The cylindrical portion Si? of the outer sleeve is provided with spaced axially extending cuts 32 to form tongues 84. These tongues should have a width slightly less than the width of the slots 76, so as to be received within them when the tongues are inwardly deformed, as shown on the left hand side of FIGURE 8.

It is evident that this form of the invention provides an interlock between the outer tubular member 12D and the inner tubular member 14D, preventing relative rotation, and that when it is desired for any purpose to remove the inner tubular member, the tongues 84 can be bent outwardly, whereby the inner tubular member can easily be unscrewed and removed. While, in this illustration, a pair of diametrically opposed tongues 84 are received in a pair of diametrically opposed slots 76, the number and spacing of the tongues and slots can be varied, to permit locking at selected angular relative positions of the inner and outer tubular members.

In the form of the invention shown in FIGURE 8, it is evident that the inner tubular member 14D must be inserted from the lower end of the outer tubular member 12D because of the enlarged outer diameter of the cylindrical portion 74. However, if it is desired to insert the inner tubular member from the upper or outer end, the external diameter of the cylindrical portion 74 can be made not to exceed the diameter of the crests of the The advaninternal threads 24D of the outer tubular member 12D. It is apparent that alterations and modifications can be resorted to without departing from the scope of the invention included within the appended claims. Y

We claim: f 1. An insert comprising a pair of intertting 'tubula members, the outer of said members provided with a counterbore at each end thereof, said outer member being v internally and externally threaded, the outer threads being adapted to engage an internally threaded bore in a parent body,rone end of said outer member including external serrations adapted to penetrate the wallof the bore of the parent body to lock said member, in the bore, the inner of said members being externally and internally threaded, the external threads =of .said inner member being in threaded engagement with the `inner threads of the outer member, said inner member being provided with a counterbore and external locking projections at one end thereof adapted to engage the counterbore of the outer member opposite the outer member end which is provided with external serrations, said counterbored portion of said inner member being deformed into non-rotatable locking engagement relative to the outer member.

2. An insert as defined in claim 1, in which the internal threads of the inner member include at least one deformed root convolution to Vprovide an interference t with a threaded fastener received therein.

3. An insert comprising a pair of interfitting tubular members, the outer of said members provided with a counterbore at each end thereof, said outer member being internally and externally threaded, the outer threads being adapted to engage an internally threaded bore in a parent body, one end of said outer member including external serratious adapted to penetrate the wall of the'bore of the parent body. to lock said memberin the bore, the inner of said members being externally and internally threaded, the external threads of said inner member being in threaded engagement with the inner threads of the outer member, said inner member being provided with a counterbore adapted to engage the counterbore of the outer member opposite the outer member end which is provided with external serrations, said inner member being in nonrotatable locking engagement relative to said outer member by welded connection between the counterbored end of said inner member and the adjacent counterbored end of said outer member.

4. An insert comprising a pair of intertting tubular members, the outer of said members provided with a counterbore at each end thereof, said outer member being internally and externally threaded, the outer threads being adapted to engage an internally threaded bore in a parent body, one end of said outer member including external .serrations adapted to penetrate the wall of the bore of the parent body to lock said member in the bore, the inner of said members being externally and internally threaded, the external threads of said inner member being in threaded engagement with the inner threads of the outer member, said inner member being provided with a counterbore at one end thereof juxtaposed the counterbore of the outer member opposite'the outer member end which is provided with external serrations, said counterbored end of said outer member opposite said end which is provided with external serrations being provided with inwardly deformed tongue means, said counterbored end of said inner member being provided with slot means, said inner member being in non-rotatable locking engagement relative to Said outer member by said inwardly deformed tongue means `carried by said outer member being interlocked with said slot means carried by said inner member.

5. In a two-piece insert for connection with a body of material having a surface, the combination of an external body having outer threads and a threaded bore, one end of said outer body forming a radially and outwardly deformable head having a counterbore, a plurality of lockv ing projections on said head, a counterbore at the opposite end of said outer body, said opposite end kbeing radially and youtwardly deformable and an externally Vand internally threaded locking member intheV bore of said outer body, the external threads of said locking member being in engagement with the A'threads of said internal bore of deformed into locking engagement with the counterbore Yof, the outer member at the end of said outermember opposite said locking formations carriedithereby, aV cir- `cumferential portion of said internal looking v'member `said outer member, said inner Vmember having a connter- Y, bore forming a thin. walland adapted tobe outwardly' References Cited in the le of this patent UNITED STATES PATENTS Furlan Nov. 28, Rosan Dee.,11, Neuschotz Apr. 24, Rosan July 17, Neusehotz May 14, Rockwell Mar. 17, Rosan Sept. 18, Flumerfelt/ Nov. 27, Rosan et al.k Mar. 19,

FOREIGN PATENTS Norway Sept. 30, 

1. AN INSERT COMPRISING A PAIR OF INTERFITTING TUBULAR MEMBERS, THE OUTER OF SAID MEMBERS PROVIDED WITH A COUNTERBORE AT EACH END THEREOF, SAID OUTER MEMBER BEING INTERNALLY AND EXTERNALLY THREADED, THE OUTER THREADS BEING ADAPTED TO ENGAGE AN INTERNALLY THREADED BORE IN A PARENT BODY, ONE END OF SAID OUTER MEMBER INCLUDING EXTERNAL SERRATIONS ADAPTED TO PENETRATE THE WALL OF THE BORE OF THE PARENT BODY TO LOCK SAID MEMBER IN THE BORE, THE INNER OF SAID MEMBERS BEING EXTERNALLY AND INTERNALLY THREADED, THE EXTERNAL THREADS OF SAID INNER MEMBER BEING IN THREADED ENGAGEMENT WITH THE INNER THREADS OF THE OUTER MEMBER, SAID INNER MEMBER BEING PROVIDED WITH A COUNTERBORE AND EXTERNAL LOCKING PROJECTIONS AT ONE END THEREOF ADAPTED TO ENGAGE THE COUNTERBORE OF THE OUTER MEMBER OPPOSITE THE OUTER MEMBER END WHICH IS PROVIDED WITH EXTERNAL SERRATIONS, SAID COUNTERBORED PORTION OF SAID INNER MEMBER BEING DEFORMED INTO NON-ROTATABLE LOCKING ENGAGEMENT RELATIVE TO THE OUTER MEMBER. 